<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
<style>
    /* id选择器 特性值/权重 100 */
    #one{
        margin: 20px;
    }
    /* 类选择器 特性值 10 */
    .two{
        margin: 40px;
    }
    /* 标签选择器 特性值 1 */
    div{
        width: 100px;
        height: 100px;
        background-color: salmon;
        margin: 10px;
        /* margin: 10px !important; */
    }

</style>

</head>
<body>
    <div>hello</div>
    <div id="one" class="two" style="margin: 30px;">hello</div>
    <div>hello</div>
    <div>hello</div>


</body>
</html>